//
/******************************************************
        File name:    main.c
        Author:       Bitat (陆叁柒)
        Gitee :       https://gitee.com/bitat
        Email :       737166381@qq.com
        History:      2023/1/5
*******************************************************/


#include <stdio.h>

int main()
{
    int i = 0;
    int sum = 0;
    int input = 0;
    
    for(i=0; i<5; i++)
    {
        scanf("%d",&input);
        sum+=input;
    }
    
    printf("%.1f",sum/5.0);
    
    return 0;
}
